成分与致密度对陶瓷材料近红外反射率影响的数值模拟

Numerical Simulation of Near-infrared Reflectivity of Ceramic Materials with Different Components and Density

为研究不同成分陶瓷材料在不同致密度下近红外反射性能的变化规律,对烧结过程中陶瓷材料的颗粒分布进行抽象建模,并利用电磁波时域有限差分方法(Finite-difference time-domain,FDTD)分析了模型结构的反射率规律。结果表明,单组分和二组分陶瓷材料在相对疏松时,因大量孔隙/颗粒界面的存在,均表现出较高的反射率。材料致密化后,对于单组分体系,由于孔隙缩小甚至消失,反射界面数量大幅度减少,进而导致其反射性能发生骤降。而对于二组分体系,尽管致密化过程同样减少了孔隙与颗粒形成的反射界面数量,但二组分之间折射率的差异保证了异质界面的存在,故其反射率在致密化以后仍可保持较高水平。

Some numerical models have been built to study the variation of near-infrared reflectivity of ceramic materials with different component and density.In these models,the different sintering stages are described as different particle density,and the reflectivity is analyzed by Finite-Difference Time-Domain method.The results indicate that the reflectivity of both one-component and two-component is higher in models with lo-wer density since the existence of lots of pore-particle interfaces.However,the reflectivity of one-component models is dropped sharply after densifying shrinkage and pores disappearance.Due to the existed interfaces between the two components in two-component models,the reflectivity of two-component models is still maintaining at a high level,even though densification is happened.